Explain one study related to localization of function in the brain

Localisation of function in the brain is a key idea of modern psychology, and the studies which have revealed which areas are specialised are some of the most famous in Psychology. The idea of localisation of function was introduced in the Principles of the BLoA page, so re-read that first if you need a reminder. The picture below is also a great introduction.

Credit: Aiden Sammons

﻿Command Term in Focus - Explain﻿

﻿﻿"Give a detailed account including reasons or causes"﻿﻿

﻿Level 2﻿

﻿When writing an 'explain' essay (8 marks) make sure you give reasons and causes for a behaviour or psychological phenomenon (e.g. detailed reasons and causes linking Tan's speech defects to the brain damage he suffered)﻿

Broca (1861) - "Loss of
Speech, Chronic Softening and PartialDestruction of the Anterior Left Lobe of the Brain"

Paul Broca

﻿Broca's famous case study was conducted on a stroke victim named Tan because the only word he could say was “tan” (following this case, a condition such as Tan's would become known as "Broca's aphasia"). Broca studied the difficulties that Tan had with his communication for many years, but it was not until he died age 51 that he was truly able to investigate the damage to Tan's brain in detail.

An autopsy revealed a lesion in the left frontal lobe. The specific placement is now called Broca’s area, and has been found to be responsible for the co-ordination of the motor (muscle) movements required to produce coherent speech.

Conclusion: Broca concluded that parts of the left frontal lobe, including the area damaged in Tan, had the role of the “language center” in our brain. Many subsequent studies have confirmed the role of Broca's area in the production of speech.

More broadly, the case study was one of the first to conclusively show that certain functions can be localised in specific areas of the brain.﻿

Tan's brain, with an undamaged brain below for comparison.

﻿Key vocab check﻿

﻿aphasia: a disorder caused by the damage of some areas of the left hemisphere of the brain. Symptoms of aphasia are the inability to understand and construct complex sentences, phrases or words. Usually aphasia is caused by sudden head injury or a stroke.

Broca’s aphasia: a type of aphasia where patients lack the use of syntax while talking (aggrammatism)

Broca’s area: controls speech production, articulation and the understanding of language. This is located in the left frontal lobe.﻿

Assignment 1 - summarise the case report

The brief report above does not really give you very much detail about the case. Far more useful is the case report, which you can see below. Open the file and produce a half page summary of the main facts of the case. Then write three conclusions which can be drawn from the case.

Sarah Scott - Broca's aphasia case study

The video on the right is of a British girl from Sarah Scott, who suffered a stroke at 18 and developed Broca's aphasia as a result.

There are a series of videos on YouTube, documenting Sarah's slow recovery over the course of a number of years. It makes for moving viewing at times, but it is a great example of the sorts of difficulties that Broca's aphasia can involve.

What is triangulation?

An example of types of triangulating evidence

Triangulation means using a wide variety of types of evidence in order to draw conclusions. It is a key aspect of sciences such as psychology, where we have multiple techniques which can be used when investigating behaviour.

Throughout the BLoA sections on this site, we will be looking at possible cases of triangulating evidence for conclusions that can be drawn, and trying to assess how these extra pieces of information can help us to make more sophisticated conclusions about the functions of the brain.

﻿Triangulating evidence for Broca's study﻿

﻿As this section is only ever going to be examined as an 8 mark question, you will not require too much triangulating evidence. However, it's good practice to always be drawing links across your syllabus...

We will meet a number of other functionally specialised areas of the brain over the remainder of the BLoA course. The hippocampus and its role in memory is the obvious one (for example in the pages on '﻿cognition and physiology﻿' and 'environment and physiology'), but we will also mention specialised functions of the orbitofrontal cortex in feeling pleasure in Berridge and Kringelbach's study on the ' brain imaging' page.

All of these studies help to provide further evidence for the principle of localisation of function in the human brain. They DON'T show that all functions are localised (and even the functions that they deal with are almost never totally localised in one place), but they do illustrate how the brain has numerous specialised areas for processing and performing specific functions.﻿

Assignment 2 - 8 mark practice essay

Re-read your notes on this study, then answer the question below from memory. Try to write around 2/3 of a page. REMEMBER THE COMMAND TERM! Make sure you answer it accurately for an 'explain' question.

Explain one study related to localization of function in the brain (8)

Revision

Extension

Look up Wernike's aphasia for an interesting related speech impairment. Rather than the production of speech, this involves the understanding of speech, and the production of sentences which make sense.